As 1917 opened, World War I continued its stalemate on the Western Front. Both sides were seeking a way to alter the situation. With it very probable that the United States would soon enter the war against Germany, the German secretary of state, Arthur Zimmerman, searched for a way to make America’s entry relatively inconsequential. Thus, he sought the assistance of Mexico, in case the United States joined the Allies. If Mexico joined in the plan laid out in this telegram, the American forces would be tied up at home. To achieve optimal results, plans had to be made in secret. Although it was written in code, Zimmerman’s failure to insure that the telegram securely reached the German embassy in Mexico was a major mistake on his part. Even though the United States declared war three months after the telegram, it was a forgone conclusion that the America forces would enter the war against Germany once the discovery of the telegram made it public that Germany was plotting directly against the United States.

As 1917 opened, World War I continued its stalemate on the Western Front. Both sides were seeking a way to alter the situation. With it very probable that the United States would soon enter the war against Germany, the German secretary of state, Arthur Zimmerman, searched for a way to make America’s entry relatively inconsequential. Thus, he sought the assistance of Mexico, in case the United States joined the Allies. If Mexico joined in the plan laid out in this telegram, the American forces would be tied up at home. To achieve optimal results, plans had to be made in secret. Although it was written in code, Zimmerman’s failure to insure that the telegram securely reached the German embassy in Mexico was a major mistake on his part. Even though the United States declared war three months after the telegram, it was a forgone conclusion that the America forces would enter the war against Germany once the discovery of the telegram made it public that Germany was plotting directly against the United States.

When World War I broke out in late July 1914, Germany attempted to gain a quick victory against France, as had happened in the Franco-Prussian War of 1870–71. While its forces did gain significant territory, it did not accomplish its goal. By late September 1914, the British and French forces (the leading Allied nations) had stopped the German advance. Defensive fortifications were established on both sides, the famous trenches of World War I. For most of the next three years, British and French forces tried to displace the Germans, with little success. The Germans could not move forward, either. Leaders on both sides sought ways to end the stalemate. For the Allies, the hope was that the United States would ultimately join its side in the war. Germany had to do something that would either keep this from happening or lessen the impact if it did.

Mexico had been in the midst of a civil war since 1910. At various times, three or four armies confronted, or assisted, one another. By the end of 1916, the civil war became a three-way struggle, with President Venustiano Carranza having gained control of central Mexico, weak opposition from Pancho Villa in the north, and Emiliano Zapata operating in the south. One thing all three had in common was their mistrust of the United States. In addition to the traditional discontent resulting from the Mexican-American War (1846–48), in 1914 the United States had captured the port city of Veracruz and temporarily occupied it; and then in 1916, American troops invaded northern Mexico in response to cross-border actions by Villa. As a result, many Mexicans supported the idea of war against the United States. It was this sentiment that Zimmerman hoped to tap into, with the plans briefly outlined in his telegram to the German ambassador to Mexico. According to reports, President Carranza did seriously consider the offer made by Zimmerman. However, in the end, he reached the conclusion that even if all the forces in Mexico worked together, Mexico could still not be successful in a war against the United States.

As for the United States, the interception of this telegram was a major step toward its entry into the war in Europe. Once the British decoded the telegram, they waited a month before passing it on to the Americans. The US government received a copy of the telegram after Germany made a public announcement that it would attack all ships approaching Great Britain and had begun doing so. Just over a month after the telegram was made public in the United States, with several American ships having been sunk, a declaration of war was passed by Congress and the United States entered the war against Germany in April 1917.

Arthur Zimmerman was born in East Prussia on October 5, 1864, and died on June 6, 1940. A lawyer, he joined the Foreign Office in 1893. After a few years in Berlin, Zimmerman was posted to China in 1896. Having returned to Berlin in 1911, he became an undersecretary of state, and in November 1916, he was named secretary of state. He participated in the 1914 discussions within the German government as to whether to support Austria-Hungary, and supported the kaiser’s decision to give the support that led to World War I. Most of Zimmerman’s efforts to either strengthen Germany or diminish the Allies failed. The only exception was giving Vladimir Lenin safe passage to Russia, which led to peace on the Eastern Front. In part because of the exposed telegram, and in part because he had been ineffective in most diplomatic initiatives, Zimmerman was forced to resign in August 1917.

As of January 1917, the leaders of Germany were still determined to be victorious in the war. Although various peace initiatives had been floated in several forms, none gained any widespread support. In order to win, Germany could not afford to have the United States join its forces with Great Britain and France. In the minds of the German leaders, the weakness of the American Army had been shown in Pershing’s inability to capture Pancho Villa during the earlier (and ongoing) incursion into Mexico. The fact that the United States Army had been given official authorization to invade Mexico in search of Villa, gave the Mexican government more than enough reason to declare war on the United States. In line with this, Zimmerman offered support for Mexico if Mexico would invade the United States, not only in response to recent American military actions, but in order to regain territory lost to the United States in the Mexican-American War.

The telegram begins by informing the German Minister to Mexico that the decision has been made to “begin submarine warfare unrestricted.” All the German leaders knew that this would lead to America’s entry into the war. The sinking of the Lusitania in 1915 created a great outcry in the United States against unannounced submarine attacks against civilian ships. This reached a peak when the Sussex, a ferry in the British Channel, was sunk in 1916. To keep the United States out of the war, Germany pledged not to attack certain types of ships. Going back on this pledge, in order to cut supply lines to the British Isles, meant that the Americans would likely enter the war. At the end of the telegram, Zimmerman gives the ambassador, and the Mexican president, assurances that once the new submarine campaign is underway, Britain’s days in the war are numbered.

The second paragraph of the telegram proposes an alliance between Mexico and Germany. Germany will provide “financial support” in order for Mexico to get back Arizona, New Mexico, and Texas. Since the American forces had had only marginal success during their ongoing incursion, Zimmerman hoped that Mexico would become sufficiently unified and obtain the military supplies needed to effectively confront the United States. President Carranza was then warned by some of his advisors that the United States was too strong to attack, and by other advisors that Mexico had strength enough to win. In any case, he was advised against an attack because it would be too disruptive to have so many Anglos, harboring clear US sympathies, living in what would become northern Mexico. Ultimately, Carranza had no interest in the proposal, instead focusing on domestic concerns.

The third paragraph proposes what it is that Germany would want in exchange for helping Mexico in a war against the United States. (Nowhere in the telegram does it state the real reason why Germany wanted Mexico to undertake these actions: to delay American forces from going to Europe.) Early in the war, Japan had joined with the British and French in declaring war on Germany. Japan had wanted, and obtained, power over the German-controlled territory and colonies in the Pacific. Japan joined in a few naval operations against the Germans, but never sent land forces to Europe. In the telegraph, Zimmerman requests that Mexico act as a mediator between Germany and Japan, but not tell Japan that Germany has requested this action.

Germany’s ambassador was to secretly share these objectives with the Mexican president once it was clear that Germany faced an “outbreak of war with the United States.” Overall, the proposal by Zimmerman put virtually nothing at risk for Germany and everything on the line for Mexico. Even if the telegram had not been intercepted, it is doubtful that the resentment that Mexico had toward the United States would have been enough to initiate an invasion of it.

Believing that Mexico was ready to join in military action against its belligerent neighbor to the north, the United States, Zimmerman tried to initiate discussions on Mexican-German unity against America. However, the plot totally backfired when the telegram was intercepted by the British and shared with American leaders. As a result, the Zimmerman Telegram was one of the two factors that pulled the United States into the First World War against Germany. The other was the decision by German leaders, mentioned in the telegram, to attack all shipping going to Great Britain. Zimmerman demonstrated the German civilian leaders’ anxieties regarding the potential the United States had to tip the balance of power, even if the military leadership believed that it might take years for the American forces to be a major threat. Obviously, the German military leaders were incorrect in their assessment, while Mexican President Carranza, in rejecting the proposal, understood the imbalance between the United States and Mexico.

The other point that clearly comes through in the proposal, and is evident in the lack of positive response by Mexico, is this imbalance of power. Historically, the nineteenth-century movements by Americans into Texas, that territory’s independence, and then the Mexican-American War, demonstrated that Mexico was unable to stop an American push into territory that Americans desired. During the Mexican Revolution in the early twentieth century, the United States blockaded Mexican ports, occupied the city of Veracruz, and then sent troops into northern Mexico. The various presidents of Mexico had been helpless to stop these actions. While Zimmerman wanted to tap into the discontent that this caused within Mexico, the realists in the Mexican government understood that a full-scale war would not help to regain Mexican territory or restore Mexicans’ wounded pride. They understood that the Zimmerman proposals would only help Germany. As a result, the telegram was not only a public relations nightmare for both Germany and Mexico when it was printed in American newspapers, but its stipulations had no great appeal to any Mexican leader desiring to stay in power.

• National Archives. “Teaching with Documents: The Zimmerman Telegram,” Washington, DC: US National Archives and Records Administration, n.d. Web. 3 June 2014.
• National Security Agency. “The Zimmerman Telegram [Unclassified Version].” Cryptologic Quarterly. Fort Meade, MD: National Security Agency, 43–52. n.d. Web. 3 June 2014.
• Tuchman, Barbara W.The Zimmerman Telegram. New York: Random House, 1985. Print.